The present invention relates to a magnetic head position determining device for a cassette tape player.
A conventional magnetic head position determining device of the same general type to which the invention pertains is constructed as shown in FIG. 1. In FIG. 1, reference numeral 1 designates a substrate. A position determining pin 2 and a cassette holding stand 3 are secured to the substrate 1. A leaf spring 4 is also secured to the substrate 1 with a screw 5. Reference numeral 6 designates a head substrate which is movable in the horizontal plane with respect to the substrate 1. A head 7 is mounted on the head substrate 6. Reference numeral 8 designates a compact cassette.
FIG. 1 shows the cassette 8 loaded in the player. That is, the pin 2 is engaged with a position determining hole 9 formed in the cassette 8, the cassette is placed on the cassette holding stand 3, and the cassette is urged by the leaf spring 4 in a direction perpendicular to the axis of the pin 2. Thus, the position of the cassette 8 is determined with respect to the substrate 1.
The head substrate 6 is moved towards the cassette 8 thus loaded until the head substrate 6 abuts the pin 2 so that the position of the head 7 with respect to the substrate 1 is suitably determined while the head 7 abuts against the magnetic tape (not shown) in the cassette 8 and which is exposed through the front opening of the cassette 8.
In the conventional magnetic head position determining device, the position of the head 7 with respect to the cassette 8 is determined by the position of abutment of the head substrate 6 with the pin 2. Therefore, the device is disadvantageous in that the accuracy of the head position is not as high as desirable. Also, the above-described conventional cassette position regulating device suffers from a difficulty that it is intricate in construction because it requires the leaf spring 4 and the screw 5 for securing the leaf spring 4 to the substrate.
The invention further relates to an operating mechanism for a portable cassette tape player, and more particularly to an operating mechanism suitable for a small portable cassette tape player.
A conventional portable cassette tape player of this type is as shown in FIG. 2. In FIG. 2, reference numeral 11 designates a compact cassette; 12, a reproducing head (or a recording and reproducing head); 13, a mechanical body base; and 14a, 14b and 14c, operating buttons. The head 12 is mounted on a movable substrate 15. The movable substrate 15 is mounted on the mechanical body base 13 in such a manner that it can swing about a fulcrum 16. The operating buttons 14a, 14b and 14c are provided on one side of the mechanical body base 13. Further in FIG. 2, reference numeral 17 designates a pinch roller which is rotatably mounted on a pinch roller arm 18. The pinch roller arm 18 is mounted on the mechanical body base 13 in such a manner that it is swingable about a fulcrum 19. The arm 18 is urged clockwise by a spring or the like (not shown) so that its free end is abutted against a pin 20 fixed to the movable substrate 15. FIG. 2 shows the cassette 10 loaded in the player, but not the case, etc.
When, after the cassette 10 is loaded in the mechanical body base 13, the reproducing button 14a is depressed, the movable substrate 15 is turned counterclockwise, as a result of which the reproducing head 12 is abutted against the magnetic tape (not shown) while the pin 20 is released from the arm 18. Therefore, the arm 18 is turned clockwise and the pinch roller 17 is pushed against a capstan 11, which is rotated at a constant speed. At the same time, a tape winding reel shaft (not shown) is rotated to wind the tape, and signals are reproduced from the tape.
The above-described portable cassette tape player is disadvantageous in that it is large in size because the operating buttons 14a, 14b and 14c protrude from the mechanical body base 13 (which is substantially equal in size to the frame (not shown) of the player).
Another aspect of the present invention relates to a drive mechanism for a cassette tape player, and more particularly to a drive mechanism using an endless belt laid over pulleys in a cassette tape player.
A conventional drive mechanism of the same general type as the invention is constructed as shown in FIG. 3. In FIG. 3, reference numeral 31 designates a cassette holding a magnetic tape; and 32 a base plate of a cassette tape player. A motor 33 is fixed to the plate 32, and a capstan 34 is rotatably mounted on the plate 32. On the rear side of the plate 32, a flywheel 35 is mounted on the capstan 34, and a pulley 36 is fixed to the shaft of the motor 33. The flywheel 35 includes an integrally formed pulley. A rubber endless belt 37 is laid over the pulley of the flywheel 35 and the pulley 36.
In the cassette tape player drive mechanism thus constructed, the motor 33 drives the capstan 34 so that the magnetic tape is run by the capstan 34. If, in the drive mechanism described above, the tension of the belt 37 is insufficient, it is difficult to transmit the torque of the motor to the capstan 34. Therefore, in general, the belt 37 must be kept under a relatively high tension. Since the belt 37 is kept under a high tension, the belt 37 tends to deteriorate with time, as a result of which the reproduced sound includes distortion due to wow and flutter.
Another conventional operating mechanism for a portable cassette tape player is shown in FIG. 4. In order to show the interior of the player well, the case, etc., are not shown in FIG. 4. The player shown in FIG. 4 is in its signal reproducing state.
In FIG. 4, reference numeral 41 designates a conventional compact cassette; and 42, a substrate on which a head substrate 43 is mounted in such a manner that it can move towards and away from a cassette 41. A reproducing (or recording and reproducing) head 44 is mounted on the head substrate 43. The head substrate 43 is urged by a mechanism (not shown) so as to move away from the loaded cassette 41, and normally it is abutted against a stop (not shown). Further in FIG. 4, reference numeral 45 designates a pinch roller arm on which a pinch roller 46 is rotatably supported. The arm 45 is rotatably mounted on a pin 47 fixed to the substrate 42. The arm 45 is urged clockwise by a mechanism (not shown) such that the end portion of the arm 45 is abutted against a raised part 48 of the head substrate 43. Levers 51 and 52, which have operating buttons 49 and 50, respectively, are mounted on the substrate 42 in such a manner that they are slidable in the direction of the arrow A. A tension spring 53 is connected between the lever 51 and the head substrate 43.
Further in FIG. 4, reference numeral 54 designates an arm which is rotatably mounted on a pin 55 fixed to the substrate 42 and is abutted against a raised part 43a of the head substrate 43 and a raised part 52a of the lever 52; 56a and 56b, reel shafts; 57, a capstan; and 58a and 58b, positioning pins. The reel shafts, the capstan and the positioning pins are engaged with the holes (not shown) of the cassette loaded in the player. The lever 52 extends through a hole 59 formed in the substrate 42.
In the portable cassette tape player thus constructed, by depressing the operating button 49 in the direction of the arrow A, the head substrate is moved through the spring 53 in the direction of the arrow A so that the head 44 is abutted against the magnetic tape in the cassette 41 loaded as shown in FIG. 4. When the head substrate 43 is moved as described above, its raised part 48 is also moved away from the arm 45, as a result of which the pinch roller 46 is abutted against the capstan 57 with the magnetic tape therebetween, and the magnetic tape is run. Thus, the player has been placed in the signal reproducing (or recording) state.
When, under this condition, the operating button 50 is pushed in the direction of the arrow A, the head substrate 43 is moved through the arm 54 in the direction opposite to the direction of the arrow A (against the elastic force of the spring 53). As a result, the head is moved away from the magnetic tape while the pinch roll 46 is moved away from the capstan 57. In this state, the magnetic tape is run at high speed; that is, in the fast forward mode.
As is apparent from the above description, the conventional portable cassette tape player operating mechanism requires the arm 54 to run the magnetic tape in the fast forward mode, and therefore it is disadvantageous in that it is intricate in construction.